1. Field of the Invention
The present invention relates to a magnetic head device for use in a disc drive for a magnetic disc, and in particular to the structure in a head carriage of the magnetic head device.
2. Description of the Prior Art
In a disc drive device for writing and reading information in a magnetic disc, a so called floppy disc, there has been used a head carriage for mounting a magnetic head for moving along in the radial direction of the floppy disc and a drive device which writes in and reads out the information at a predetermined position of the rotating magnetic disc by the rotation of the disc.
FIGS. 1 and 2 are views showing the structure of a conventional head device. A pair of cores 3a and 3b is respectively supported by an upper slider 5a and a lower slider 5b in a carriage 1. The magnetic disc 10 is represented as shown. In the arrangement, the width of the core is from 0.8 to 1.2 mm wide and each of the cores 3a and 3b is pressed onto the opposing side slider so that the head is in contact with the slider. However, since the sliding width of the core is wide and the area of the connected portion of the magnetic disc is wide, such as the amount of 3.5.times.6 mm, there tends to occur spacing which is disadvantageous for high density recording.
In order to solve the above mentioned problem, as shown in FIGS. 3 and 4, an arrangement of supporting the cores 3a and 3b respectively in the sliders 5a and 5b was eliminated and another arrangement in which the cores 3a and 3b were bonded to the respective end surfaces of the sliders 5a and 5b were suggested. In this arrangement the bonded areas of both of the cores 3a and 3b and each of the sliders 5a and 5b can be small so as to eliminate the spacing problem, but since the condition between the height of the core and the height of the slider becomes unbalanced, a rotational moment of the head in the radial direction of the disc is generated so as to vibrate the head. Therefore, as shown in FIG. 2, a means for making the vibration of the head small is adapted in the manner that the top portion of the upper slider 5a is pressed by a pivot 2 of a pressing means at generally the middle position between the upper core 3a and lower core 3b. However, although the vibration can be made small, there is a problem that the output of at least one side of the upper and lower sides of the magnetic disc is lowered. That is, it can be seen that with the changing of the pressing point on the magnetic disc by the pivot 2, the output of the lower side is lowered when the pressing point is closer to the upper core 3a and the output of the upper side is lowered when the pressing point is closer to the lower core 3b.